Apparatus for the manufacture of mica-coated fibrous material



Dec. 25, 1928. v 1,696,397

E. HAEFELY APPARATUS FOR THE MANUFACTURE OF MICA COATED FiBROUS MATERIAL Filed July 12, 1924 In rewvfar EHaefag y f/W 44M m w;

Patented Dec. 25, 1928.

PATENT OFFICE,

EMIL HAEFELY, OF BASEL, SWITZERLAND.

APPARATUS FOR THE MANUFACTURE OF MEGA-COATED FIBROUS MATERIAL.

Application filed July 12, 1924, Serial No.

This invention relates to an apparatus for the manufacture of mica-coated fibrous ma terial for electric insulating purposes by automatically cementing small sheets or scales of mica on to a web of fibrous material, and has for its object to provide an improved simple apparatus for this purpose.

The improved apparatus comprises means for covering a conveyor band with the mica scales and means for transi erring the latter from the conveyor band to the fibrous material by a pressing action with the assistance of an agglutinant. The apparatus operates in such a way that an endless con veyor band running over guides, is covered with mica scales and is brought into engage.

ment with a band or strip of fibrous matcrial, and together with this band or strip and with an agglutinant is conveyed to the active region of a heated pressure roller, so that the sheets or scales of mica are, by means of the pressure exerted by this roller, transferred from the conveyor band with the aid of the agglutinant to the Web of fibrous material.

The invention is illustrated by way of example in the accompanying drawing, the single figure of which is a vieug in side elevation of one form of apparatus embodying the invention.

Referring now to the drawing, the web, band or strip, of fibrous material, which on one side is coated with a layer of agglutinant, indicated at (1i. An endless conveyor band Z) constructed, for instance, of linen or other suitable material, co-operates with the web of fibrous material, and in operation is continuously drawn over a number of rollers, being maintained continuously stretched by means of tension rollers c and (Z in a known manner The mica scales or sheets are distributed over the surface of the conveyor band I) as the latter moves over a supporting plat form 6. This distribution may be effected in various known ways, for example, by blowing the mica scales on to the band by means of a blower, by distributing the scales by hand, or by shaking, by letting the mica scales fall in a shower from a suitable height, or in any other suitable manner.

When the conveyor band 6 covered on its outer side with the mica scales passes under a pressure exerting roller f the scales come in contact with the layer of agglutinant on theweb ot fibrous material or, and by 725,723, and in Switzerland July 28, 1923.

means of the roller f and the tension in the conveyor band 6, are pressed on to the fibrous material. i

The pressure roller f is heated to a greater or less extent and will require to be highly heated when using a solid agglutinant which is softened by the heating action of the roller, and thus melted on to the fibrous material, so as to permit the cementing of the mica scales transferred from the conveyor band to the fibrous material under the tension of the conveyor band. The agglutinant, however may also be applied to the fibrous material in a fiuid condition, and if this be effected by a special machine, the roller f must give off suificient heat to soften the agglutinant to a binding condition. It is moreover, also possible to apply the agglutinant in a liquid condition directly to the fibrous material before its contact with the conveyor band, in which case only so much heat must be given off by the roller f as is necessary to drive off moisture and the solvent of the agglutinant. In all cases the pressure roller serves also as guiding member for the agglutinating material or web a to preheat same and to thus prepare its agglutinant before it comes in contact with the mica covered band 6, for securing the agglutinating efi'ect when the two webs a, Z) join together at the pressure surface of the roller, where combined pressure and heat act to finally melt the agglutinant and to cement the mica scales on the fibrous material (1 After passing the pressure or mica trans ferring point the conveyor ban d and the web of fibrous material travel together at the same speed over any desired number of guide rollers and separate from one another after leaving the roller 9.

At this point, the conveyor band Z1 continues its endless course, while the web of fibrous material coated with mica is wound on to a drum h, at the same speed as the uncoated material is unwound from the drum The mica need not be distributed uniformly over the conveyor band, but it should be observed that the band upon coming into contact with the web of fibrous material should everywhere he covered with at least one layer of mica. As only the mica scales nearest to the agglutinant adhere to the web of fibrous material there is an excess of mica conveyed to the roller g, this excess of mica being released at this point and owing to its own Weight falling into a collector 1c.

The removal of the excess of mica may also be effected by means of a rotary shaking device on of known type.

The pressure roller 7 may be arranged to be raised from the conveyor band I) by means of a known lever operated eccentric device a.

\Vhat I claim is:

An apparatus for the manufacture or micacoated fibrous material for electric insulating purposes, comprising an endless conveyor band with mica scales freely distributed thereon, tensioning means for said conveyor band, means to supply an agglutinating Web of fibrous material and a combined pressure and heating roller arranged to serve first as guiding anL preheating member for said agglutinating weband then to apply and press, While heating, said agglutinating Web of fibrous material upon the mica carrying conveyor band substan tially as and for the purpose described.

In witness whereof I have hereunto signed my name this 30th day of June, 1924.

EMIL HAEFELY. 

